Saturday 13 December 2008 19.01 EST
First published on Saturday 13 December 2008 19.01 EST

They are young, smart, organised, committed and, if they are allowed to have their way, they would like to save the world. No longer is an environmentalist a geeky elderly man in socks and sandals or a dreadlocked traveller in a rainbow jumper. Britain's new vanguard of eco-warriors are predominantly in their twenties, they are articulate and knowledgeable and techno-aware.

Monday's demonstration by 57 young protesters from the environmental group Plane Stupid at Stansted Airport in Essex took many by surprise, not least by the audacity of the direct action in getting through extremely tight security and managing to briefly close down a busy airport. Protesting against airport expansion in the UK, Plane Stupid later produced some very media-savvy representatives to put across their case.

For many people it was their first encounter with what has been an underground but growing phenomenon in Britain. Over the past two years a new social movement to rival any protests of the past has been steadily growing, young campaigners and activists who are dedicated to achieve what previous generations have not - stopping climate change. And it is not only in environmental activism that the UK is leading the world but also in the science, with a growing band of dedicated young scientists working against the clock to discover the truth behind climate change.

People like Ellen Fry, a 26-year-old working for the Institute for Climate Change, based at Imperial College. Described by her colleagues as 'brilliant, cutting edge and totally dedicated', she is working on the impact of rainfall on ecosystems and spends much of her time in a field. 'I've worn out three pairs of wellies this year so far!' she says.

'My work is in plant response to climate change, when eco-systems shut down. I was at school when I went to a lecture by an Exxon Mobil executive and I was terrified. I thought I have to do something useful with my life, so I moved into biology.'

She says had she more time she would even consider activism herself although 'perhaps universities wouldn't like their researchers getting arrested'.

Jasmin Karalis, 24, a climate campaigner who helped hijack a train carrying coal to the Drax power station in North Yorkshire in June, takes being arrested as a downside of the work she cares passionately about. She says she finds the political system deeply frustrating 'because everyone thinks we have to have either capitalism or socialism and that there's nothing in between - but there is.

'It's very frightening for people to hear us say that capitalism is the problem, people can't see that there might be anything else. But this system has failed us. Even now all they will speak about at political forums is how money can be made out of this [climate change crisis]. That's shocking. That's disgusting.'

Karalis, from an Iranian family, has only recently graduated from university where she first became environmentally aware. But she refutes the idea that everyone in the movement is a spoilt middle-class kid.

'That's complete nonsense. Of course the media is talking to the most articulate ones because they have the confidence to come forward. But this is a social movement with people from all classes and all walks of life. You don't need to be Oxbridge, you need to be brave.'

Most of the activists and campaigners The Observer spoke to see no divide between the political system, social justice and climate change.

Sophie Stephens, 25, holds down a nine-to-five office job in Leeds. She uses holidays and sabbaticals for her other work, protesting against the UK's carbon emissions and helping develop Climate Camp - the annual event for environmental activists which is in its third year.

'We respect science so much and the work being done in this country is remarkable. At Climate Camp we have lots of eminent experts along to talk about the latest research to keep people fully informed,' she says.

'We have a unique opportunity as a species to pre-empt this disaster. I'm no green goddess, I cycle to work and I recycle, but change needs to happen at a higher level. It terrifies me that we hand all vital decisions about climate change and energy policies to people who believe financial sense is common sense.'

She says taking part in direct action is 'really liberating'.

'That's why we are prepared to break the law. You are suddenly in the middle of the debate and that's empowerment.'

Paul Morozzo was involved in the anti-roads protests of the Nineties. Now aged 41 and living in Yorkshire, the father of two is still a dedicated environmental campaigner and he welcomes the resurgence of a social protest movement.

'It's both new and old. It's partly inspired by older movements like the anti-roads movement, but crucially it's also inspired by the unique circumstances we find ourselves in as the growth economy hits both the ecological limits of the planet and social limits of exploitation and greed. Also there is a real desire to create new stories, the biggest one being a just solution to climate change and averting planetary meltdown. That would be a good one for the grandchildren.

'Environmental struggles in the Nineties were often characterised by intense struggles, either in defence of place, e.g. against road builders, or for early Reclaim the Streets over the creation of place. Now the place is the entire planet and a clash between what people need and what the economy needs. This grand narrative will hopefully motivate a movement equal to the task.

'Given that the government is still planning to build new coal-fired power stations and expand its airports and roads, Ed Miliband's call for a public mobilisation on climate change is a clear attempt to co-opt this growing climate movement. But people aren't daft. They realise that the suffragettes and the civil rights movement didn't win by wearing rubber wrist bands, they won because they were both broad based and willing to take risks, if necessary breaking the law. They knocked directly on power's door, in fact they knocked it down.'

Jody Boehnert runs EcoLabs, a non-profit organisation encouraging ecological literacy through design. A graphic designer, she was drawn to environmentalism through her love of nature.

'I like to hike and I find it almost unbearable to believe that we could squander all this beauty.

'I grew up in Canada. My mother was a professor and active in the feminist movement. My father lectured on the arms race. I have been concerned about global warming since I was a teenager and an activist for over a decade. I feel that we might finally be able to make some progress now. The environmental crisis has hit the mainstream. We can now make the necessary changes if we move decisively.'

'Previous generations have left us an awful mess,' she says. 'The economic successes of the past will be felt by our generation as we learn to deal with degraded ecosystems less capable of supporting life as we know it.

'In a democracy, the government can only ever make changes that are supported by the people, so it is pointless to separate "society" from "government". The problem rests in a culture that refuses to confront environmental realities. We now need to deal with the consequences of this reckless behaviour - the actions of not only previous generations but of most of our contemporaries who only give lip service to change.

'Almost all advocates of change in the mainstream media recommend small steps. Even cumulatively these actions will not stop the climate system from reaching tipping points, now just a few years away. We need to design systemic change - and we need the media to help audiences understand the importance of this agenda above all other agendas.'

If any generation is going to take the brunt of climate change it will be those who are too young to be climbing up power stations or taking PhDs in ecological science.

Joanna Courtice is a schoolgirl campaigner. Aged just 16 she has already persuaded her Cambridgeshire teachers to create an 'eco-school' and is working at trying to encourage awareness and activism among other schools in her area.

'It's about small steps, one thing at a time,' she says. 'For me it's hard persuading other girls my age because they think they have to give things up that they like. It feels like I'm putting them on a diet no one wants to go on.

'But I am 16 and now I can fight back against what people have let happen to the planet. For me it's 16 years of no one fighting. I have to make up for that.'

A history of eco protest

Sizewell, 1980s

During the inquiry into the construction of Britain's last nuclear reactor at Sizewell, Suffolk, Friends of the Earth organised demonstrations against the plant's construction.

Anti-roads, 1990s

These direct action groups prevented work on the new A30 by setting up camp. Residents protested both above ground in tree houses and below it in tunnels. The camp's final resident 'Swampy' (Daniel Hooper) gained celebrity status.

Anti-GM, 1998-2004

Demonstrators, including environmentalist George Monbiot, were arrested in 2001 for criminal damage during a protest at Wales's only GM crop trial. The not guilty plea, based on acting in the public interest, brought the issue of GM crop safety into the public eye.

Anti-runway, 2007

Mass demonstrations against the expansion of Heathrow airport were held throughout the summer, with thousands of protesters camping on the site of the new runway.

Climate camps, 2008

In the wake of the success of previous ones, 'climate camps' for protesters at sites where airports and roads are due to be expanded or built have grown in number and popularity. Richard Rogers